准备发布 v0.1.0

- 添加 Apache-2.0 许可证
- 添加 CHANGELOG.md 变更日志
- 添加 SECURITY.md 安全策略
- 添加 README.zh-CN.md 中文文档
- 添加 rustfmt.toml 代码格式配置
- 添加 scripts/pre_publish_check.sh 发布检查脚本
- 更新 Cargo.toml 元数据（分类、关键词、文档链接）
- 完善 README.md 示例代码
- 优化 SM2/SM9 性能和测试覆盖率

SECURITY.md

@@ -0,0 +1,55 @@
+# Security Policy
+
+## Supported Versions
+
+| Version | Supported |
+|---------|-----------|
+| 0.3.x   | Yes       |
+| < 0.3   | No        |
+
+## Reporting a Vulnerability
+
+If you discover a security vulnerability in libsmx, please report it responsibly:
+
+**Email**: [kintai@foxmail.com](mailto:kintai@foxmail.com)
+
+**Please include**:
+- Description of the vulnerability
+- Steps to reproduce
+- Affected versions
+- Any potential impact assessment
+
+**Response timeline**:
+- Acknowledgment within **48 hours**
+- Initial assessment within **7 days**
+- Fix release within **30 days** for confirmed issues
+
+## Scope
+
+The following areas are considered in-scope for security reports:
+
+- **Timing side-channels**: Any operation whose execution time depends on secret data (private keys, plaintext, nonces)
+- **Memory safety**: Buffer overflows, use-after-free, or uninitialized memory reads (note: this crate uses `#![forbid(unsafe_code)]`)
+- **Key material leakage**: Private keys or intermediate secret values not properly zeroized
+- **Cryptographic correctness**: Deviations from GB/T standards that weaken security guarantees
+- **Authentication bypass**: Incorrect MAC/tag verification in GCM/CCM modes
+
+## Out of Scope
+
+- Performance issues that don't affect security
+- Dependencies' vulnerabilities (report upstream)
+- Attacks requiring physical access to the device
+
+## Security Design
+
+libsmx employs the following defenses:
+
+- **Constant-time operations**: All secret-dependent code uses `subtle::ConstantTimeEq`, `ConditionallySelectable`, and fixed-iteration loops
+- **No table lookups for S-boxes**: SM4 uses boolean circuit bitslice implementation to prevent cache-timing attacks
+- **Automatic key zeroization**: All private key types derive `ZeroizeOnDrop`
+- **No unsafe code**: `#![forbid(unsafe_code)]` is enforced at the crate level
+- **Complete EC formulas**: SM2 point addition uses branch-free complete addition formulas (Renes-Costello-Batina 2016)
+
+## Disclosure Policy
+
+We follow coordinated disclosure. Please do **not** open public GitHub issues for security vulnerabilities.